Teach Us to Number Our Days

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The Ancient Hebrew Calendar


Gen 1:14, 16  And God said, Let there be lights in the firmament of the heaven to divide

the day from the night; and let them be for signs, and for seasons, and for days, and

years: ---And God made two great lights; the greater light to rule the day, and the

lesser light to rule the night: he made the stars also.


One of the main functions of the heavenly bodies is to divide time into different unit

lengths. This make human life and the carrying out of our day to day activity much more

manageable. But the more basic question is: What is time? Don't tell me what it does, tell

me what it "Is". When we boil it down, time is the comparison of one moving object to

another moving object.

When we look at a wrist watch we are looking at moving objects that

give us a sense that time is progressing. When we stare at an object that is completely

motionless its hard to get a good sense of time. Einstein delved into motions of objects  

relative to the motion of other objects. His Theory of Relativity has contiued to fasinate

scientists ever since.


The main divisions of time for the ancient Hebrews and for modern man is the Year, the

Month, and the Day. In the study of Biblical Chronology and Biblical Prophecy it is vital

that we understand the basic definitions of each of these as defined in scripture. In

Genesis Chatper 1 the "day" is repetitively defined six times as "and the evening and the

morning were were the : 1st, 2nd, 3rd, 4th, 5th, and 6th day". What could be clearer? 

A period of darkness (the evening) and a period of light (the daytime) equals one "Day".

Yet many people want to re-define each of the 6 creation days in Genesis

as a massively long age so that they can reconcile evolutionary ages with the Genesis

account. This does violence to scripture and empties the meaning of "the evening and the  



The ancient Hebrew months were not calculated but were a result of direct observation of

the moon. A New Moon and the beginning of a new month began with the first crescent of

light as the moon emerges out of its own black shadow.


A new moon can generally be seen during the first 45 minutes after sunset. During the

next 29 to 30 days the moon will wax and wane through its phases.

The problem with making a mathematical model of the new moon crescent is that the moon

emerges from its deepest shadow (astronomical conjunction of the Earth, Moon and Sun)

in varing number of hours that range from 17 to 24 hours (translation time). This 

mysterious variation is caused by the differences between Apogee (when the moon is

furthest from the earth) and Perigee (when the moon is closest to the earth). 

At closer distances to the earth the moon appears bigger in

the sky and the gravity of the earth-moon system is stronger. This causes the orbital

velocity to be slightly greater and allows the moon to emerge from its own shadow sooner.

Thus, in constucting the mathematics of the Hebrew new moons I use a published

algorithim that establishes the distance from the earth to the moon for any day and time

in history.[1] The correlation between the moon translation time and the earth-moon

distance between perigee and apogee has the form of a straight line equation (mx + b).


Combining the moon's translation time with the time of astronomical conjunction gives us

the precise time that the moon is far enough out of the earth-to-sun line to create a

potential visible crescent. If this potential crescent new moon time occurs after the moon

has already dropped below the horizon (approximately 6:45 pm) we know we have to wait

for the next evening for it to be visible to a human observer.


To validate the mathematics of my Hebrew new moon computer model we found that the

seven observed and recorded Nisan new moons in Babylon from 28 to 34 AD produce

nearly the same (mx + b) equation of correlated translation times (using sum of the least

squares best fit).


With Hebrew Lunar months defined as beginning with the "new moon" crescent we turn our

attention to the definition of a Biblical "year". Some Bible researchers in order to

calculate Daniel's 69 weeks of years prophecy feel compelled to use a non-literal so-called

"Prophetic Year" of 360 days. However, literal years in the Bible are tied to the Growth

Cycle of plant life.

   2 Kings 19:29 “And this shall be a sign unto thee, Ye shall eat this year such things as

   grow of themselves, and in the second year that which springeth of the same; and in

   the third year sow ye, and reap, and plant vineyards, and eat the fruits thereof” (see

   also Isa 37:30).


It is the repetitive circling of the Earth to the same place in its orbit about the sun and

not to some arbitrary 360 day position that is in focus. Since plants know nothing about

"Prophetic Years" the literal Hebrew year has an over-riding bias toward what we call a

Solar Year.


A Hebrew year is based on 12 or 13 lunar months each year so a literal Bible year is

what we call a Solar-Lunar Year. 12 Lunar months is close to 354 days which is far short

of a Solar Year comprising 365 1/4 days. Yet 13 Lunar months is close to 384.5 days

which is longer than a Solar Year. So how is it that the Hebrews were able to keep their

calendar from drifting over the years and how could they keep it in step with the natural

plant cycle which is based on the Solar Year?   


The answer is related to the the question, when does a year end and a new year begin?

The solar cycle, like a circle, has no beginning or end unless an arbitary reference point is

selected on the circle as a defined ending/beginning point. For the ancient Hebrew

calendar we have to go back to the Land of the Pharaohs to a point in time where God

defined the beginning of the year reference point, the year was 1491 BC :


In that year the Jewish nation was led by Moses out of Egypt and were headed by God's

grace to the promised land. This great migration is known in history as the "Exodus".

This occured on the 15th day of the Eygptian month of Abib. God revealed to Moses

and Aaron His choice for the beginning reference point for the Hebrew year:

  Exodus 12:1-2 And the LORD spake unto Moses and Aaron in the land of Egypt,

                   saying, This month shall be unto you the beginning of months:

                   it shall be the first month of the year to you.

  Exodus 13:4  This day came ye out in the month Abib.

  Esther 3:7    In the first month, that is, the month Nisan, - - -   

The word Abib according to Strongs Concordance means:

  1) fresh, young barley ears, barley

  2) month of ear-forming, of greening of crop, of growing green 


Thus, the beginning of the first month of the Hebrew year was forever after linked to  

and controlled by the embedded nature of a plant known in sciece as Hordeum Spontaneum

and its domesticated version Hordeum Vulgare. I call it God's little green computer.

During the Passover feast comemorating the Exodus, the Jews were instructed by God :

    Ex 23:10-11

    Speak unto the children of Israel, and say unto them, When ye be come into the land 

    which I give unto you, and shall reap the harvest thereof, then ye shall bring a sheaf

    of the firstfruits of your harvest unto the priest: And he shall wave the sheaf before

    the LORD, to be accepted for you: on the morrow after the sabbath the priest shall

    wave it.

Because of the requirement to offer the first sheaf of the grain harvest (Barley) to the

Lord it was then incumbent upon the priest to check the Barley corn to insure that it was

ripe enough on Nisan 1 such that 2 weeks later it could be ground into flour even if it had

to be parched. The barley kernels on Nisan 1 could not be watery ripe nor even soft

dough or worm stage but must be what is referred to as hard dough or Abib stage.

                                   Soft Dough or Worm Stage Pinch Test


Records of Abib stage in the Jerusalem area over the last 9 years have been published.

From this data we find that Abib always occurs in the window of March 10 to April 8.

Thus, God's little green Barley computer was used by the priest to pick the right month

for Nisan. If toward the end of the 12th month Adar the Barley corn was too green, the

priest would simply declare they needed another 30 days (another lunation) making

that Adar month 59 days long. Eventually the Jews refered to this additional lunation as

another Adar month which, after the times of Christ, they began to call it Ve-Adar or

Beit Adar (the 13th month, or leap month).


Thus, by alternating back and forth from 12 lunations/year to 13 lunations/year as 

directed by the barley crop maturity, the ancient Jewish calendar can be shown over a 38

year or more time period to have an "average year" that is as precise as the scientific

solar year of 365.24 days.


Combining all of the above it is possible to reach back to any year in history and re-

create the ancient Hebrew calendar comprising 12 or 13 (as the case may be) lunar  

months.  The computer Hebrew Calendar Program I developed converts Julian dates to

Gregorian dates and then checks to see if the 1st day of the month Nisan is within or

closest to the Barley ripe window of March 10 to April 4. The program's output below  

has identified a barley ripe condition for the year 30 AD and has labled the header of

the calendar as " *BARLEY RIPE ".    

   Hebrew days are divided into four 6 hr segments with Julian Dates changing at midnight.


The 7 Biblical "Feasts of the Lord" occur on a specific day of the month as follows :

Passover : 15th day of the month (Full Moon) Nisan at night.

Unleavened Bread : 15th day of the month (Full Moon) Nisan during the day, for 6 days.

First Fruits : the first Sunday after the 14th day of the month Nisan during the day.

Pentecost : 50 days inclusive from First Fruits which is always a Sunday during the day.

Trumpets : 1st day of the month (New Moon) Tishri during the day.

Day of Atonement : 10th day of the month Tishri during the day (a fast, no feasting).

Tabernacles : 15th of the month Tishri during the day and night for 7 days. 


The Jewish "Feasts of the Lord" are not just memorials of the past but they were also

prophecies of the future. These prophecies are not ordinary prophecies. In each case

they are prophecies of events involving the Collision of Humans with God Himself. The

precise days of these feasts in the various Hebrew lunar months were locked in place

thousands of years ago and documented in Leviticus 23. The new testament is clear that

in the case of 5 of the feasts the prophectic fulfilment occurs on the vary day of the

feast. Two of the feasts, Trumpets and Day of Atonment, are yet future. For more on

this topic click on the "Prophecy" tab at the top of this web-page.



[1] Chapront-Touzé, Michelle and Jean Chapront. Lunar Tables and Programs from 4000 B.C. to A.D. 8000 . Richmond: Willmann-Bell, 1991. ISBN 0-943396-33-6.

If you need the most precise calculation of the Earth-Moon distance for use in identifying ancient crescent New-moon Hebrew Calendar dates, you are probably going to end up with Chapront-Touzé. Their book presents the ELP 2000-85 theory which, while less accurate than ELP 2000-82 for observations near the present epoch, it has been tested for stability over much longer time spans representing ancient history back to the epoch 4000 BC. This material is intended for experts in positional astronomy and computation. If you can't figure it out, please don't ask me for help, its far too involved.